Nowadays, opening ZIP files on Windows is a very run-of-the-mill type of affair, but back when compressed folders were starting to pop up, that wasn't exactly the case. Support for ZIP files first appeared on Windows with the Microsoft Plus! 98 pack, and it was originally the work of Dave Plummer, a former Microsoft engineer who has since left the company.

But before he willingly left Microsoft, Plummer nearly got fired, and it was all because of ZIP support in Windows.

ZIP support wasn't developed by Microsoft

As Plummer shares on his personal YouTube channel, while working for Microsoft, he had many side projects that he would distribute and sell online by himself, something he had been doing prior to joining Microsoft and that he got approval for when he joined. While at Microsoft, Plummer began working on a shell extension that would allow Windows to display the contents of a ZIP file as if it were a typical folder (much like how we know it today), which he sold under the name Visual Zip.

This, and Plummer's experience with the Windows shell, got him promoted to the shell team at Microsoft, but that's where the trouble began. One member of the shell team took offense to the existence of Visual Zip as a side project, and reported Plummer to HR in order to get him fired. This quickly spread and Plummer and his management were unsure of how to secure his job.

Thankfully, he decided to write to the executive vice president of Microsoft at the time to ask if there was any problem with him selling Visual Zip as a side project. Thankfully, the response was that there was no problem here, and Plummer got to keep his job.

So how did it become a part of Windows?

After all that, Plummer kept selling Visual Zip as before, but about six months later, he got a call from someone else at Microsoft asking him if he was the developer of Visual Zip. As it turns out, Microsoft wanted to buy the program off of Plummer to integrate it directly into Windows, but the person calling him had no idea that he was actually a Microsoft employee.

Eventually, that got sorted out, and Plummer met with the responsible teams at Microsoft, agreeing to sell VisualZIP for the initial offer. This was because not only did he not want to risk losing his job, but if Microsoft were to develop or acquire a tool from someone else, that would put VisualZIP in competition with Microsoft's own product, which wasn't compatible with the terms of his employment.

Interestingly, Plummer has mentioned on his Twitter (now X) profile that ZIP support in Windows has remained mostly unchanged ever since its initial implementation, meaning the way it works today is still pretty much the same (which might be why it's far from ideal). That being said, Microsoft recently added support for many more archive types, like RAR, with Windows 11 version 23H2 so the company is finally doing something to improve support for compressed archives.